EXHIBIT 24: POWER OF ATTORNEY The undersigned Directors of Paychex, Inc., do hereby constitute and appoint B. Thomas Golisano their true and lawful attorney and agent, to execute the Paychex, Inc., Annual Report on Form 10-K for the fiscal year ended May 31, 1999, for us and in our names as Directors, to comply with the Securities Exchange Act of 1934, and the rules, regulations and requirements of the Securities and Exchange Commission, in connection therewith. Dated: August 13, 1999 /s/ Steven D. Brooks ------------------------- Steven D. Brooks Dated: August 13, 1999 /s/ G. Thomas Clark ------------------------- G. Thomas Clark Dated: August 12, 1999 /s/ David J. S. Flaschen ------------------------- David J. S. Flaschen Dated: August 16, 1999 /s/ Phillip Horsley ------------------------- Phillip Horsley Dated: August 12, 1999 /s/ Grant M. Inman ------------------------- Grant M. Inman Dated: August 11, 1999 /s/ Harry P. Messina, Jr. ------------------------- Harry P. Messina, Jr. Dated: August 12, 1999 /s/ J. Robert Sebo ------------------------- J. Robert Sebo